Abrasive articles are used in the preparation of any of a variety of surfaces prior to painting or other surface treatments. In the preparation of such surfaces, various abrasive articles may be used to abrade the existing surface to thereby maximize the ability of the surface to bond with coatings such as paint and the like. Coated abrasive paper, cloth, or vulcanized fiber discs (typically mounted on a powered right-angle tool) are all suitable articles for the foregoing abrasive application. Available abrasive discs, while being sufficiently aggressive and capable of accomplishing the needed preparation of the surface, typically have relatively short useful lives and frequently leave visible grinding marks on the surface. Consequently, additional surface preparation is often needed to remove the grinding marks prior to the application of paint or other coating. This additional corrective surface preparation includes a finishing step using finer grades of coated abrasive discs or nonwoven abrasive surface conditioning articles to sufficiently decrease surface roughness. This two step grinding effort is both labor and time intensive, and it is desirable to at least reduce the need for the use of finer grade abrasives and, in certain abrasive applications, to eliminate the need altogether.
Nonwoven abrasive surface conditioning articles have been used in a wide variety of abrasive applications and are known to leave acceptable surface finishes, and nonwoven abrasive surface conditioning articles generally have long useful lives. In most surface conditioning applications, however, traditional nonwoven articles, when used alone, are not aggressive enough to adequately clean the surface to the extent needed.
Nonwoven and coated abrasive articles have been described in the patent literature.
U.S. Pat. No. 2,958,593 (Hoover et al.) describes low density open nonwoven fibers abrasive articles having a high void volume (e.g. low density). The nonwoven webs of the '593 patent are comprised of short fibers bonded together at their points of mutual contact to form a three dimensional integrated structure. Fibers may be bonded to one another with a resin/abrasive mixture, forming globules at the points of mutual contact while the interstices between the fibers remain substantially unfilled by resin or abrasive. The void volume of the disclosed structures typically exceed 90%.
U.S. Pat. No. 3,688,453 (Legacy et al.) describes abrasive articles such as belts suitable for off hand and automated article finishing. The belts comprise a lofty nonwoven web that is attached to a woven backing by needle tacking. The web is impregnated with resin and abrasive. According to Example 1, the webs are coated with a resin/abrasive slurry which is then dried to provide the finished article. The resin/abrasive is applied to achieve a dry coating weight 169 grains per 4 inch by 6 inch pad (708 g/m.sup.2) and then is coated with a second abrasive/adhesive slurry at 78 grains per 4 inch by 6 inch pad (327 g/m.sup.2).
U.S. Pat. No. 4,331,453 (Dau et al.) describes and abrasive articles comprising a lofty, nonwoven, three dimensional abrasive web adhesively bonded to stretch-resistant woven fabric with a polyurethane binder. The resin coating weights for the articles of the '453 patent, as stated in Example 1, are about 70 grains of an adhesive composition per 4 inch by 6 inch pad (293 g/m.sup.2) followed by final abrasive-adhesive slurry at a dry coating weight of 225 grains per grains per 4 inch by 6 inch pad (942 g/m.sup.2).
U.S. Pat. No. 5,178,646 (Barber, Jr. et al.) describes coatable thermally curable binder precursor solutions modified with a reactive diluent and an abrasive articles incorporating such binder precursor solutions. The coated abrasive articles of the '646 patent include a flexible backing such as a paper sheet or a cloth backing.
U.S. Pat. No. 5,306,319 (Krishnan et al.) describes surface treating articles utilizing an organic matrix such as nonwoven web that is substantially engulfed by a tough, adherent elastomeric resinous binder system. The articles of the '319 patent principally comprise surface treating wheels.
European Patent Application 0716903 A1 describes a coated abrasive product comprised of base resin coat, abrasive mineral grains and a size resin coat all applied on flexible backing material consisting of a nonwoven fiber mat. The nonwoven fiber mat is formed into a flat, wear and tear resistant backing by means of a binder or by the superficial dissolving or fusing of fibers. An abrasive layer comprising abrasive grain may be coated onto one or both sides of the nonwoven fiber mat.
In general, the art has failed to provide an abrasive article comprising an nonwoven substrate useful in the preparation of surfaces wherein the article is capable of being both sufficiently aggressive while providing a long useful life. Moreover, the art has failed to provide such an article which can also complete certain surface treating operations in a single step to provide an acceptable finish with reduced effort.
In light of the foregoing, it is desirable to minimize the amount of effort required in the preparation of certain surfaces prior the application of coatings such as paint, for example. It is desirable to provide an abrasive article useful in the preparation of surfaces wherein the article is capable being sufficiently aggressive and has a long useful life. Preferably, such an article can complete certain surface treatment operations in a single step to provide an acceptable finish in a minimized amount of time. It is also desirable to provide a method for the manufacture of the foregoing articles.